A radio communication system of a previous type is described in JP-A-2000-92541. FIG. 9 shows the previous-type radio communication system described in the patent publication. In FIG. 9, the previous-type radio communication system is configured to include a multi-mode radio 801, a cable network 802, a cable telephone 803, a network 804 for a radio communication system A, a base station 805 for the radio communication system A, a cell 806 for the radio communication system A, a network 807 for a radio communication system B, a base station 808 for the radio communication system B, a cell 809 for the radio communication system B, and a relay device 810 for relay use between the base station 805 of the radio communication system A and the base station 808 of the radio communication system B.
The multi-mode radio 801 is available for communications with the radio communication systems A and B. The cell 806 of the radio communication system A and the cell 809 of the radio communication system B are in close proximity to each other or overlapping each other. The base station 805 of the radio communication system A transmits, to the base station 808 of the radio communication system B via the relay device 810, monitor information about monitoring of information such as channel occupation or position registration in the cell at appropriate time intervals, and system information about control channel or others in the radio communication system A. Similarly, the base station 808 of the radio communication system B also transmits, to the base station 805 of the radio communication system A via the relay device 810, the monitor information about monitoring of information such as channel occupation or position registration in the cell at appropriate time intervals, and the system information about control channel or others in the radio communication system B.
When the multi-mode radio 801 in a standby status for communications or incoming calls in the radio communication system A moves into the cell 806 of the radio communication system A, the base station 805 of the radio communication system A forwards the monitor information and the system information about the radio communication system B provided by the base station 808 of the radio communication system B to the multi-mode radio 801.
This is expected to allow the multi-mode radio 801 to have the monitor information and the system information in advance about the base station of the radio communication system being available for switching, and utilizing such information is expected to facilitate switching to the radio communication system B.
The problem with such a previous-type radio communication system is that, for the multi-mode radio 801 to receive information from the base station 808 of the radio communication system B being a switching destination, the base station 808 of the radio communication system B is required to provide information to the base station 805 of the radio communication system A via the relay device 810. For the purpose, a cable connection has to be established between the base stations 805 and 808 via the relay device 810. Moreover, when a radio communication system C is newly provided with a base station in the cell 806 of the radio communication system A and in the cell 809 of the radio communication system B, a relay device is required to be newly provided to establish a cable connection to provide system information about the radio communication system C to the base station 805 of the radio communication system A and the base station 808 of the radio communication system B.